package com.jie.utils;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.security.MessageDigest;
import java.util.Random;

public class CommonUtil {
    public static String
    getIpAddr(HttpServletRequest request) {
        String ipAddress = null;
        try {
            ipAddress = request.getHeader("x￾forwarded-for");
            if (ipAddress == null ||
                    ipAddress.length() == 0 ||
                    "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress =
                        request.getHeader("Proxy-Client-IP");
            }
            if (ipAddress == null ||
                    ipAddress.length() == 0 ||
                    "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress =
                        request.getHeader("WL-Proxy-Client-IP");
            }
            if (ipAddress == null ||
                    ipAddress.length() == 0 ||
                    "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress =
                        request.getRemoteAddr();
                if
                (ipAddress.equals("127.0.0.1")) {
                    // 根据⽹卡取本机配置的IP
                    InetAddress inet = null;
                    try {
                        inet =
                                InetAddress.getLocalHost();
                    } catch
                    (UnknownHostException e) {
                        e.printStackTrace();
                    }
                    ipAddress =
                            inet.getHostAddress();
                }
            }
            // 对于通过多个代理的情况，第⼀个IP为客户端真实IP,多个IP按照','分割
            if (ipAddress != null &&
                    ipAddress.length() > 15) {
                // "***.***.***.***".length()
                // = 15
                if (ipAddress.indexOf(",") > 0)
                {
                    ipAddress =
                            ipAddress.substring(0, ipAddress.indexOf(","));
                }
            }
        } catch (Exception e) {
            ipAddress="";
        }
        return ipAddress;
    }
    public static String MD5(String data) {
        try {
            java.security.MessageDigest md =
                    MessageDigest.getInstance("MD5");
            byte[] array =
                    md.digest(data.getBytes("UTF-8"));
            StringBuilder sb = new
                    StringBuilder();
            for (byte item : array) {

                sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
            }
            return sb.toString().toUpperCase();
        } catch (Exception exception) {
        }
        return null;
    }

    /**
     * 获取随机验证码
     * @param len
     * @return
     */
    public static String getRandomCode(int len){
        String sources="0123456789";
        Random random=new Random();
        StringBuilder build=new StringBuilder();
        for (int i = 0; i < len; i++) {
            build.append(sources.charAt(random.nextInt(9)));
        }
        return build.toString();
    }

    /**
     * 获取时间戳
     * @return
     */
    public static long getCurrentTime(){
        return System.currentTimeMillis();
    }
}
